1. Field of the Invention
The present invention relates to a cooling system and method for cooling a battery in a vehicle.
2. Background Art
When a battery is used to provide power to an electric motor to drive a vehicle, the temperature of the battery can increase significantly when the motor is operating for extended periods of time. The increase in battery temperature may be compounded when the battery is confined to relatively small, enclosed spaces. Increases in battery temperature can reduce battery charge efficiency and impede battery performance. If the battery is not cooled, battery life and fuel economy may suffer. Reducing battery usage may partially alleviate this condition, but this can affect vehicle performance and fuel economy.
Typically, vehicles have a passenger air conditioning system to cool the passenger compartment. The passenger air conditioning system includes a compressor, a refrigerant line and a heat exchanger. One way to address high battery temperatures is to use at least a portion of the passenger compartment air conditioning system to cool the battery. Because the air conditioning system is used to cool the passenger compartment, the same compressor can be used to cool the battery, but with a different refrigerant line and heat exchanger. Inefficient use of the passenger compartment air conditioning system to cool the battery, however, can adversely affect the fuel economy of the vehicle.
Thus, a need exists for a cooling system and a method of cooling a battery in a vehicle that can efficiently cool both the passenger compartment and the battery.